Aiming and guiding command set



Dec. 10, 1968 LQBOLKOW ET AL 3,415,464

AIMING AND GUIDING COMMAND SET Filed Sept. 18, 1957 2 Sheets-Sheet l INVENTORS ATTORNEY6 Dec. 10, 1968 l... BOLKOW ET AL 3,415,464

AIMING AND GUIDING COMMAND SET Filed Sept. 18, 1967 I 2 Sheets-Sheet 2 ATTORNEYS United States Patent Ofice 3,415,464 AIMING AND GUIDING COMMAND SET Ludwig Bolkow, Stuttgart-Flughafen, and Hans Bender,

Weil am Rhine, Germany, assiguors to Bolkow Gesellschaft mit beschrankter Haftung Filed Sept. 18, 1957, Ser. No. 684,820 6 Claims. (Cl. 2443.11)

This invention relates to an aiming and guiding command set adapted to be used for the remote control of flying bodies by the target coincidence method.

The control of remotely guided flying bodies by the target coincidence or three-point method usually is accomplished by the gunner adjusting a control member on the remote guiding device to so influence the trajectory of the flying body that he sees the latter in coincidence with the target. If he succeeds in maintaining coincidence of the flying body with the target throughout the flying time, the target will be hit.

While the control method described excels by requiring a minimum of equipment, it has serious shortcomings which are to be demonstrated in the following paragraphs. If a flying body is to be guided to a definite trajectory with great accuracy and within a minimum of time as required, the control properties of said flying body must be known, and its flying direction relative to the line of collimation at any given moment and hence also the momentary deviation and the rate of change thereof must be measurable. If these data are known continuously, they can be used to compute the remote-control command which brings the flying body as quickly as possible into coincidence with the target.

The application of the control system described above does not meet these conditions, On the basis of his observations of the missile course and target movements the gunner can merely give a guiding command by feel, it being left to his experience to estimate the correct magnitude of the command.

What renders this estimation much more diflicult is the fact that equal deviations of the flying body from the line of collimation appear different to the gunner at various distances of the gunner from the flying body.

Looked upon from the point of view of the present invention, the method described above has the disadvantage of requiring ample experience on the part of the gunner. The latter needs a very thorough and time-consuming training, which becomes expensive as it involves a great deal of practice firing.

Nevertheless, the gunner will never be in a position to guide the missile into the target in the shortest possible time. That is feasible only with computed command data.

It is the purpose of the present invention to remedy this shortcoming by making available to the gunner a sighting device enabling him by means of a simple measuring process requiring no special knowledge, to supply the input values, required for producing the optimum commands, in a form unobjectionable from the point of view of control engineering, to a computer coupled to the sighting device.

According to the invention, two images of the object area comprising the target and the flying body are produced on each other. One of these images is adapted to be so moved relative to the other that the target image in the one and the flying body image in the other can be continuously moved into coincidence. The remote-control command for the flying body is derived from the shifting of the two images. The two images may be produced purely optically or, very generally, by means of a device using electromagnetic waves to generate the images directly or through intermediate images. The shifting of one image relative to the other can be accomplished by 3,415,464 Patented Dec. 10, 1968 an optical-mechanical, or electrical device or by a combination of the two methods. The remote-control command to be produced from the relative shifting of the two images is derived by additive combination of the movement features of the target and the flying body and the rates of change thereof.

In doing so the respective distances of both bodies from the location of the sighting device are taken into consideration. As soon as the flying body has attained the line-of-sight course, a supplementary command taking into consideration any 'out-of-trim of the flying body is produced by continuous integration of the commands.

Also, a combination is imaginable in which the image of the target is produced by an image tube and the image of the flying body by a photo-optical device. Coincidence of the two images as required for producing the command is then obtained either by an optical-mechanical deflection of the photo-optical image or by an electric-magnetic or capacitive influence on the electronic image. Alternatively, each image can be generated by an image tube and the two images combined to form a dual image on the fluorescent screens by means of photo-optical elements, coincidence of the two component images as required for deriving the command being accomplished by means of electric influence on the electronic images.

According to a preferred embodiment of the object of the invention, the optical apparatus for generating the two images consists of an arrangement known in the art, where two parallel glass plates are disposed at an angle to the direction of vision, of which one is partially pervious and remains stationary during the measuring process, whereas the other has a specular finish and is mounted on gimbals. Provided on the specular-finish plate are plate movement measuring devices. Additional devices which may be used in this optical apparatus are prisms, pairs of rotatable wedges or telescopes. Other features of the object of the invention will be apparent from the following description and appended claims.

When the flying body has a lateral deviation y from the line of sight, the observer at the sight sees it at an angle to from the line of sight. With equal deviation y, the angle to is different for different distances x. Thus, a primary measurement can be made only of w=y/x.

For the method according to the invention, it is assumed that the speed v of the flying body is known. If t is the flying time from the start to the moment of each measurement, the distance or, if the speed is constant, x=v-t, is known. Thus, the lateral deviation y=x-w can be calculated from the measured angle w. Thus, it is the primary function of the set to measure the angle w.

According to the method of the invention, this measurement is made by producing a dual image of the object area by optical means and arrangements known in the art, similar to those used in earlier constructions of con ventional range finders.

According to the method of the invention, the two images are moved relatively to each other so that image points of one component image are caused to coincide with image points of the other image. If then, the component images are so moved that the target image of one component image is caused to coincide with the flying body image of the other component image, a measurement of the angle defined above is obtained. Such shifting of one component image is accomplished by mechanical movement of optical constructional elements, such as the rotation of a mirror, prism or rotatable wedge, or by shifting of a lens. In the case of an electron-optical image,

it is accomplished by electromagnetic or capacitive influence on the electronic image. In the first-named instance, the movements of the optical constructional elements are linked to the magnitude of the angle to by the laws of geometrical optics. In the case of the electron optics, the current intensity of the electromagnetic deflecting elements or the magnitude of the voltage of the capacitive deflecting elements provides the datum of the angle to.

The two component images of the dual image being identical according to the laws of geometrical optics it is necessary in most instances to employ physical-optical methods, such as coloring or modification of the degree or direction of polarization, in order to make them distinguishable by the observer.

In order to extend the range of application of the sighting method to invisible light wave lengths, such as for example ultraviolet or ultrared and thermal rays, the dualimage method is to be extended also to such images of the object area as are produced on the screens of image converters, it being also imaginable that only one of the image points of interest, that is, either the target image or the flying body image, is generated by the image converter, whereas the other one is generated by a photooptical arrangement.

As the sighting device according to the invention measures the angle between two points in the object area, the spacing of the entrance pupils of the two optical systems producing the component images of the dual image must be sufficiently small, preferably zero.

If this manner, the angle to has been determined, the remote-control command must be computed therefrom. The flying body deviation y as shown above is proportional to the angle or for a given distance x.

The command is then obtained from an additive combination of the value of the deviation y and its variation in time, that is, the differential quotient dy/ dz: g. If K designates the command value at the time t where a and b are constants depending on the properties of the set. As the deviation y is proportional to the angle to when the distance x is constant, to may be used in place of y in producing the command, but it should then be considered that 40 must be multiplied by the distance x to obtain the deviation y. There exist two possibilities of taking into consideration the influence of the distance.

(1) The values obtained in determining w are multiplied by x. This gives the deviation y and thus the possibility of computing K (2) The value of w is used to compute a command The final command K, is then obtained from K by multiplication of the latter by x or an equivalent operation.

Both ways are feasible and have their peculiarities which make the one or the other appear more advantageous depending on the conditions of the apparatus used.

If, for example, w is determined optically-mechanically and the command value is also obtained mechanically through the use of an adding device, it seems suitable to form the input values for the latter from the mechanical indications of the measurement of w by interposition of a multiplication device. The latter is, in principle, a lever transmission with variable transmission ratio.

If the values of w are obtained by electrically measuring the mechanical movements of the optical measuring elements for example by Potentiometers, the multiplication of w by x can be represented by increasing the potentiometer voltage proportionally to x. Corresponding considerations also apply to capacitive or inductive methods.

If to is represented by the magnitude of a current or voltage resulting from the influence exerted on an image tube image, an amplifier with a degree of amplification proportional to the distance is used. The electrical method is only reasonable, of course, if the command is also produced electrically.

The construction of the lever transmision of the multiplication device and of the equivalent voltage variation in electrical methods presents difliculties, if the range of distances becomes too wide. In this case, the second possibility shown offers a way out, which becomes particularly simple, if the remote-control commands are given by impulse ratios. As a matter of fact, this is mostly the case. The commands are then taken electromechanically by a movable tap from a rotating contact device having two live commutators separated by an insulating gap. In this arrangement the insulating gap mostly is in the form of a geodesic line. Thus, if on a rotating cylinder it will be in the form of a helix, and if on a rotating disk it will be in the form of an Archimedian screw. In the former instance, the tap will be moved parallel to the cylinder axis and in the latter, radially across the disk.

If, for example, the separating line of the two commutator halves in the case of the rotating disk is formed by providing a plurality of serrations on the circumference of the disk, each serration being limited by a segment of a spiral of respective pitch and a part of a radius, a so-called sawtooth line is obtained. The tap must be movable radially by an amount so as to cover the height of a saw-tooth. The impulse ratio can then be varied from the negative unit to the positive one.

In order to compensate the decreasing magnitude (corresponding to a constant lateral deviation of the flying body) of the angle 00 serving to determine the command value K+, it is necessary to make the tooth height on the commutator disk decrease according to the same law, that is, proportional to the reciprocal value of the distance x. This has the effect that a constant impulse ratio is tapped in the case of a constant lateral deviation of the flying body. This process is equivalent to multiplying w by x. If the distance ratio is not too great, the sawtooth disk is constructed as an electro-mechanical commutator.

If, however, a wide variation of the saw-tooth height and at the same time a large number of teeth is required, the disk is constructed in the form of a diaphragm as a photo-electric commutator, of which one part is impervious and the other pervious to light. A luminous spot projected on the saw-tooth disk is scanned by a photoelectric cell. The luminous spot has then of course to be moved radially relative to the disk by means of the command computing device. An amplifier having a constant degree of amplification is required for amplifying the cell currents.

When a flying body is controlled 'by means of an aiming and guiding command set corresponding to the foregoing description, it can be demonstrated mathematically that, with the target stationary, the remote-control command becomes Zero from the moment when the flying body reaches the line-of-sight course for the first time without swinging.

Minor deviations from this course will then occur with equal frequency on all sides in the average of time, so that the average of time of the given command values will also be zero. If this is not the case, the reason is that either the target is moving or the flying body has constructional inaccuracies causing its flying behavior to be one-sided. In either instance, a continuous command must be given to keep the flying body on the line-of-sight course. The average of time of the command value then differs from zero. If, therefore, from the moment the flying body reaches the line-of-sight course for the first time, the given command values are given through an integration device, the latter can be used to adjust the tap on the command transmitter in the sense of a supplementary command. This supplementary command will then compensate the influence of the movement of the target or the constructional inaccuracies of the flying body, and its value will be correct when the time integral of the commands has become zero again.

The invention is more particularly described with reference to the accompanying drawings which show an example of construction of the object of the invention embodying the ideas outlined.

FIG. 1 illustrates the situation. The eye 8 of the gunner looks through the sight 9 to the target 10. The missile with the lateral deviation y from the line of collimation is shown at two distances x and x and indicated by reference numerals 11 and 11 respectively. One sees that, despite of equal deviation y, the missile due to different distances appears at a larger angle m in its position 11 and at a smaller angle o in its position 11 FIGURES 2a, 2b and 2c show the field of vision of the sighting device. FIG. 2a shows the image formed by the straight path of rays with the target image 10 and the flying body image 11, while FIG. 2b shows the image of the angular path of rays with the target image 10' and the flying body image 11. FIG. 20 shows a composite image formed by the images of FIGS. 2a and 2b, with the images of the two paths of rays superimposed so that the flying body image 11 and the target image 10 are in coincidence. The adjustment of the sighting device required is used to measure the angle 0:. In addition, the images 11 and 10' appear in the field of vision which are not required for making the measurement.

FIG. 3 shows schematically the construction of an embodiment of the aiming and guiding command set. Through the inclined glass plate 12, the eye 8 of the gunner observes both the target and the object area comprising the flying body. A second image is produced through the mirror 13 which is parallel to the glass plate 12. The image projected onto the mirror 13 is colored by means of a color filter 14 disposed in front of it to enable the gunner to distinguish in the dual image the components thereof. The mirror 13 is gimbal-mounted and can be adjusted by moving the handle 15 of the control lever 16. By such a movement of a suitable value, the angle to is measured as illustrated in FIG. 20.

The control lever .16 is threaded for the nut 17 to move thereon. This movement is forcibly produced by a motor (not shown) which rotates the control lever 16 about the longitudinal axis thereof. While the flying body is in flight, the nut 17 moves from its initial position near the mirror 13 in the direction of the free end of the control lever provided with the handle 15, whereby the transmission ratio between the deflection of the control lever and an addition gear associated with the nut 17 is continuously increased. In this manner, to is multiplied by x and the movement of the rod is then proportional to the deviation y.

At its connecting point 19, the rod 18 is so connected to the member'20 of the addition gear that it can travel on the gear member 20 from 22 to 23. Parts 25 and 26 of the addition gear are rigidly connected to the gear member 20. Part 26 has a cylinder 27 thereon, in which a damping piston 28 connected to the part 29 is arranged. The lever 31 is connected to the parts 25 and 29 through joints 21 and 24, respectively. Through the joint 30, a lever 32 carrying an electrical contact tap 33 is connected to the lever 31. Moreover, the joint 21 permits the lever 31 to be moved in the direction 21, 22.

If then, the rod 18 is moved in its longitudinal direction by an amount y, the gear member 20 is shifted by the same amount parallel to itself. Due to the rigid coupling of the part 25 to the gear member 20, the joint 24 also moves by the amount y. If we consider temporarily the joint 21 as fixed, the rod 32 is shifted by the amount a+b y The tap 33 on the resistor 34 moves by the same amount from its normal position, and a voltage proportional to the amount y occurs at the terminals 35.

As long as the rod 18 is moved, a force is acting at the damping device 27, 28 which according to physical laws is proportional to the speed dy/dt=y. This force moves the point 21 against the action of an elastic suspension 36 acting on the lever 31 by an amount proportional to y as long as the movement of the rod 18 continues. This displacement of the point 21 adds the amount a-l-b y to the existing displacement of the tap 33. Thus, the total shifting of the tap 33 and hence, the command voltage K obtained at the terminals 35 can be expressed by the following formula:

If as a result of these command values the missile has been brought to coincidence with the target, a relay 37 opens the switch 38.

The command current then flows through an integration motor 39. This adjusts the second tap 40 in the manner illustrated whereby a supplementary command taking into consideration the target speed or any missile out-of-trim is given. This supplementary command keeps the flying body on the line-of-sight course, if, because coincidence with the target has been accomplished, a remote-control command in the average of time is no longer given by the control lever.

FIG. 4 shows in diagram a second embodimnet of the aiming and guiding command set. Like reference numerals designate similar constructional elements to those in FIG. 3.

In contradistinction to the first embodiment illustrated, the coupling of the control lever 45 to the addition gear is characterized by a constant transmission ratio. Connected to the control lever 45 by means of a joint 46 is the rod 47, which in turn is connected by a swivel joint 48 to the gear member 20. The dependance on time of the values is taken into consideration only aft of the addition linkage at a drum controller 50. FIG. 5 shows an enlarged fragmentary view of the cylindrical drum controller 50. The drum consists of two conducting commutator parts 51 and 52 which are separated by an insulating sawtooth line 53. The amplitude of the saw teeth decreases according to a predetermined law. What is to be shown is that the dependence on time of the measuring values can be compensated by a suitably selected function of the saw-tooth amplitudes.

As illustrated in FIG. 4, the ends of a battery 54 are connected through sliding contacts 55 and 56 to the two commutator parts 51 and 52, respectively, and a tap 57 which is movably arranged on the drum controller, is connected to the neutral of the battery 54 through the terminals 58 from which the command value is transmitted to the flying body.

The drum 50 is rotated by a motor 59 at such a speed that the impulses are tapped from the drum with the frequency desired. The number of saw teeth provided on the drum must then correspond to the product of the impulse 1 frequency and the respective missile flying time t. If the deviation of the tap from the center line 00 of the sawtooth line is h (FIG. 5), the resulting command will be ab -a+b where a and b are the areas passed on the commutator parts 51 and 52. As shown above, with the deviation y constant, the control lever deflection decreases as 40, which means, however, that it decreases as l/x. If then, the saw-tooth amplitudes are also made to decrease as l/x, it is apparent that K remains constant.

However, aside from the tap 57 another tap 60 slides across the drum controller 50. Both of them are located at the same point in the direction of rotation of the drum controller or are spaced less than the width of a saw tooth apart. The lever 61 with the tap 60 is coupled to the addition gear at the joint 30 and transmits the control lever deflections to the drum controller. Moreover, the lever 61 is connected by means of the joint 62 to one end of a second addition lever '63 whose other end is moved by an integration device 65. A lever 66 carrying the tap 57 is pivoted on the pivot point 64 located in the center of the lever 63. The deflection of the tap 57 is initially proportional to that of the tap 60. The tap 57 feeds the command impulses to the flying body through the terminals 58.

When the line-of-sight course is reached, the integration device 65 begins to add the impulses tapped through 60 and thereby to adjust the bottom pivot point 67 of the second addition lever 63 in such a way that the command given is increased. As a result, an excessive impulse is transmitted to the flying body, whereby the position of the flying body relative to the target is altered in the image so that the control lever 15, 45 has to be moved in the opposite sense. The tap 60 is thus restored, too. The integration process is completed, When the tap 60 is on the center line -0 of the saw-tooth line. The flying body then flies without any control lever deflection on the lineof-sight course, and the trimming command required will have been transmitted to the tap 57 by the integration as a fixed pre-command.

The drum controller of FIG. 4 may be constructed in the form of a photo-electric switching element, as for example by forming the commutator body 50 of material pervious to light and making one commutator part in the form of a drawing which is impervious to light. This drawing may be made by photochemical methods. The sawtooth line 53 then becomes a light-dark edge, which can be scanned by a luminous spot movably mounted as a tap with the aid of an optical projection apparatus and a photoelectric cell. In the electrical circuit of the photoelectric cell, vibrated currents occur with the impulse frequency and the command value. Suitable electrical devices such as relays, amplifiers, etc., transform these currents so that they can be transmitted to the flying body. The drum controller may of course be replaced by a disk or differently shaped body.

Finally, it must be mentioned that the lateral deviation of the missile from the line of collimation has gene-rally to be split up into two components, for example, a horizontal and a vertical component, or, in the case of polar coordinates, into an absolute value and an azimuth, and that, consequently, most of the devices described above have to be duplicated.

What is claimed is:

1. A remote guide means for flying bodies by the target covering method operative with target and control devices comprising means for producing two superimposed images of the object area created by a target and a flying object, means for shifting one of the images relative to the other so that the images of the target and the image of the flying object are continuously brought into coincidence and means for delivering a control signal to said flying object indicative of the magnitude and rate of change of the deviation between the target and the flying object.

2. A remote control device according to claim 1 wherein said first mentioned means includes optical means including a pair of glass plates arranged at an angle relative to the direction of vision, one of said plates being partly transparent and stationary during measuring whereas the other plate is covered with a mirror and is cardanically rotatable around two planes lying in the rotatable axis, said guide means including control means and a pendulum movement connected to said control means.

3. A remote guide means according to claim 2 wherein said control means is connected to automatically operate the means for producing images to control the image producing from the flying object and wherein said means for delivering a control signal includes calculating means for delivering a voltage proportional to the magnitude and rate of change of the deviation.

4. A remote guide means according to claim 3 wherein said calculating means includes a calculating drive mech anism connected to and dependent on the movement of said control means.

5. A remote guide means according to claim 3 further including supplementary control means for continuous integration of said voltage starting with the moment the line-of-sight course is reached to compensate for any outof-trim of the flying object and any speed of the target.

6. A remote guide means according to claim 1 wherein said means for producing two superimposed images includes an image tube for each image and means for combining the two images to form a dual image and wherein said means for delivering a control signal includes commutator means and integrating means connected in driven relationship to said commutator means, said commutator means delivering a pulsing output signal having an amplitude indicative of said deviation.

References Cited UNITED STATES PATENTS 1,249,274 12/1917 Chandler 244-l4.5

BENJAMIN A. BORCHELT, Primary Examiner.

T. H. WEBB, Assistant Examiner. 

1. A REMOTE GUIDE MEANS FOR FLYING BODIES BY THE TARGET COVERING METHOD OPERATIVE WITH TARGET AND CONTROL DEVICES COMPRISING MEANS FOR PRODUCING TWO SUPERIMPOSED IMAGES OF THE OBJECT AREA CREATED BY A TARGET AND A FLYING OBJECT, MEANS FOR SHIFTING ONE OF THE IMAGES RELATIVE TO THE OTHER SO THAT THE IMAGES OF THE TARGET AND THE IMAGE OF THE FLYING OBJECT ARE CONTINUOUSLY BROUGHT INTO COINCIDENCE AND MEANS FOR DELIVERING A CONTROL SIGNAL TO SAID FLYING OBJECT INDICATIVE OF THE MAGNITUDE AND RATE OF CHANGE OF THE DEVIATION BETWEEN THE TARGET AND THE FLYING OBJECT. 